186Pt was tested in the framework of IBM-1 and the X(3)model.The results show that186Pt is located close to the shape phase transition point,but the B(E2)values little agree with the X(3)model.The shape evolution in the yrast states of186Pt is also discussed in detail.TRS calculation exhibits a flat bottomed potential at low spin states,but a relatively deep minimum at high spin states.It suggests that a shape evolution from vibrational mode to rotational mode happens in186Pt.The result is in agreement with the E-GOS calculation.
High spin states in 107Ag are studied via the 100Mo(11B,4n) 107Ag reaction at an incident beam energy of 60 MeV. Prompt γ-γ coincidence and DCO ratios are measured by the detector arrays in CIAE. The level scheme has been updated and a new negative band belonging to 107 Ag is identified. The new negative side band has been constructed and its configuration is tentatively assigned to πg9/2νh11/2(g7/2/d5/2).
The recoil distance Doppler shift method has been widely used in the study of nuclear structure to determine the level lifetime and absolute transition probabilities.A capacitance servo control plunger based on this method has been successfully developed by the Nuclear Structure Group of the China Institute of Atomic Energy.Three microscopes were employed to check the parallelism and can therefore guarantee a delicate measurement of the distance between the target and the stopper.This new plunger made a successful performance in the test experiment and the measured lifetime of the 2^+→0^+ transition in ^(78)Kr is in agreement with the previous value.
A mini-orange spectrometer used for in-beam measurements of internal conversion electrons,consisting of a Si(Li) detector and different sets of SmO_5 permanent magnets for filtering and transporting the conversion electrons to the Si(Li) detector,has been developed at the China Institute of Atomic Energy.The working principles and configuration of the mini-orange spectrometer are described.The performance of the setup is illustrated by measured singles conversion electron spectra using the mini-orange spectrometer.
High spin states of the odd-A87Sr were populated by the fusion-evaporation reaction82Se(9Be,4n)87Sr at a beam energy of 46 MeV. Excited levels of87 Sr have been extended up to an excitation energy of 7.4 MeV at spin31/2. The coupling of a g9/2neutron hole to the yrast states of the88 Sr core can account for the low-lying states in87 Sr. The structure of the higher spin states is discussed by analogy with those of the neighboring odd-A N =49isotones and possible configurations are proposed.
